Electrodeposition of palladium and indium

Abstract

A study has been made of the electrochemical deposition of palladium and indium onto a vitreous carbon electrode from acidic aqueous solutions, pH 0-5, containing chloride ion. The two major techniques used were cyclic voltammetry and potential step. Although scanning electron scan microscopy and experiments with Platinum and carbon microelectrodes provided essential confirmation of the conclusion. It has been shown for both metals that good deposits could be obtained and that the deposition process involves instantaneous nucleation and three dimensional growth of the nuclei. The potential, concentration and pH dependences of the kinetic parameters are reported.

Electrocatalysis of H₂ of formic acid oxidation at freshly deposited palladium centers on platinum and carbon substrates was also studied. The results would suggest that very small palladium centers (<0.6μ) are less active for H₂ evolution than bulk Pd. In contrast the palladium centers on a platinum substrate appeared to be excellent catalyst for formic acid oxidation (this is in contrast to carbon when the palladium centers are almost totally inactive). Finally, the oxidation of HCOOH and DCOOH was studied at platinum partially covered by Pb adatoms. It was confirmed that the oxidation of HCOOH is partially diffusion and partially kinetically controlled. The chemical step reflects the coverage by Pb and shows a strong kinetic isotopes effect, K_HCOOH/k_DCOOH = 2.6. Such an effect is compatible with cleavage of the C-H bond in a dissociative adsorption reaction at adjacent Pt centers as the rate determining step.

More information

Identifiers

Catalogue record

Export record

ASCII CitationAtomBibTeXData Cite XMLDublin CoreDublin CoreEP3 XMLEndNoteHTML CitationHTML CitationHTML ListJSONMETSMODSMPEG-21 DIDLOpenURL ContextObjectOpenURL ContextObject in SpanRDF+N-TriplesRDF+N3RDF+XMLRIOXX2 XMLReferReference ManagerSimple Metadata